Best open-source alternatives to Microsoft OneDrive

Syncthing is a peer-to-peer file synchronization tool designed to keep files consistent across multiple computers without relying on a central cloud service. The README emphasizes safety, security, ease of use, and automatic operation, positioning the project for individual users who want reliable syncing with minimal manual intervention. The project provides guidance for getting started, building from source, and running in Docker, and it references GUI wrappers for Windows, macOS, and Linux. It also points users to a dedicated documentation site, a forum, and a GitHub issue tracker for support and bug reports. The software is released under the MPLv2 license and includes signed release binaries, with an automatic upgrade mechanism mentioned in the README.

copyparty is a self-hosted file server aimed at turning nearly any device into a shareable storage endpoint. It is designed for people who want simple uploads and downloads from a browser, but it also exposes traditional transfer protocols such as WebDAV, SFTP, FTP, TFTP, and SMB/CIFS for clients that prefer them. The project appears geared toward personal servers, small deployments, and power users who want flexible access methods and fine-grained control over folders, permissions, and sharing. Its README highlights browser-based file management, temporary share links, thumbnails, search, media playback, and other convenience features, while emphasizing that the server itself only requires Python and that most dependencies are optional.

Puter is an open-source internet operating system designed as a personal cloud and application platform. It is aimed at people who want a self-hostable, privacy-oriented place to store files, apps, and games, as well as teams or developers building and publishing web applications and games. The project presents itself as an alternative to mainstream cloud storage services while also offering a remote desktop-style environment for servers and workstations. The README highlights a hosted version at Puter.com, but it also provides local development and self-hosting instructions using either a direct Docker run or Docker Compose setup. The software requires Node.js and npm for local execution, and the repository is licensed under AGPL-3.0.

Nextcloud Server is a self-hosted collaboration and file platform for individuals, teams, and organizations that want control over their data. It provides a central place to store files and also supports contacts, calendars, communication features, and sharing across devices. The project is designed for users who want cloud-like functionality on infrastructure they control, whether at home or in a company environment. It is extensible through a large app ecosystem, includes security features such as encryption and two-factor authentication, and can be deployed by self-installation, through hosting providers, or via appliances and preinstalled devices.

File Browser is a self-hosted web application for managing files inside a chosen directory. It is intended for people who want a lightweight, browser-based way to access files on their own server rather than using a full cloud storage platform. The project positions itself as a single-binary tool that can be installed anywhere and pointed at a local path. Through its web interface, users can browse, upload, delete, preview, and edit files. The README also notes that the project is in maintenance-only mode, with no new features planned, and directs readers to hosted documentation for setup and configuration.

restic is a command-line backup program designed for users who need reliable, secure, and efficient backups across Linux, macOS, Windows, and several BSD variants. It emphasizes ease of use, speed, verifiability, security, and storage efficiency, making it suitable for both individual users and administrators who want a straightforward backup tool that can be restored when needed. The project works by creating a repository, then storing backups as snapshots that can later be restored or mounted for browsing. It supports a variety of native backends, including local directories, SFTP over SSH, an HTTP REST server, Amazon S3, OpenStack Swift, Backblaze B2, Azure Blob Storage, Google Cloud Storage, and additional services via rclone. The README also points users to online documentation and a forum for support.

SeaweedFS is an Apache-licensed distributed file system and object store aimed at storing massive numbers of files while keeping access fast. It is designed for users who need scalable storage infrastructure, including development environments, single-node deployments, and large clusters that can grow by adding volume servers. The project combines a lightweight master/volume architecture with optional filer services for directory semantics and POSIX-like attributes. It also provides an S3-compatible API, WebDAV access, FUSE mounting, replication, erasure coding, tiered storage, and cloud integration. In addition, it ships a built-in Iceberg REST Catalog so analytics engines can query tables directly without an external metastore.

Cloudreve is a self-hosted file management system designed for people or organizations that want to run their own cloud-style file platform. It focuses on managing files across multiple storage backends, including local storage, remote nodes, and several third-party object storage providers. The project provides a web-based interface with features for uploading, downloading, previewing, sharing, and organizing files. It also supports multi-user operation, WebDAV access, background downloads through Aria2/qBittorrent, and rich online preview/editing for common file types. The README positions it as an all-in-one package for both quick local testing and production deployment.

Ente is a privacy-focused, fully open source platform built around end-to-end encrypted storage and authentication. The README presents it as a cloud-based service that lets users keep their data without trusting the provider, while also allowing self-hosting for those who want to run it themselves. The project bundles several client applications and a server in one monorepo, spanning mobile, desktop, web, and Linux platforms. It targets users who want encrypted photo management, secure document storage, and a TOTP authenticator alternative, with features such as private sharing, collaborative albums, family plans, semantic search, and background uploads.

Seafile is an open source cloud storage and synchronization project aimed at users and teams that need private file storage, sharing, and collaboration. It organizes content into libraries that can be synced independently, and it supports encrypted libraries so users can protect data with passwords they choose themselves. The README positions it as a teamwork-oriented storage platform rather than a simple file sync utility. The project includes file sync capabilities such as selective sync, delta transfers, conflict handling, and resuming interrupted uploads. It also offers collaboration features like group sharing, upload and password-protected download links, version control, metadata management, multiple file views, and integrations with office suites, a built-in document editor, a wiki, and Excalidraw. The README also points to separate repositories for the server, web UI, desktop client, mobile apps, and WebDAV component.